Practical Timber Frame Design
This class gives both aspiring and experienced timber framers additional insights into building design. Less focused on hands-on project work than most of Tillers’ timber framing classes, this seminar digs into methods, considerations, and engineering of timber frame design. A structural engineer and a timber framer will take participants through the decision making process that needs to occur prior to ordering timber. The course is also suitable as an introduction to timber frame design considerations for architectural and engineering professionals.
The course reviews the functional and architectural development of barns in the Midwest, including the timber framing traditions and structural systems that made them possible, in order to provide context and regional integrity to new designs. Students will have opportunities to visit the many timber frame structures on the Cook’s Mill campus, both historic and new, to view various solutions to design challenges for barns, shops, storage buildings and a granary.
Basic considerations for building integrity are reviewed so that completed designs can withstand the demands of internal loading as well as snow and wind, and meet building code requirements when called upon. Sizing of rafters, floor joists, beams and posts for typical farm and shop building applications is covered, and design tables for this use based on locally harvested timber species are provided. The characteristics of the different wood species typically used in timber framing and the advantages of each are presented. Joint design, layout and strength are focal points. Bracing considerations are examined. Basic foundation design is explained.
The development of various frame styles and layout systems are reviewed. Preparation of drawings is shown as an integral part of the process, from design through execution. Models – both physical and digital – are demonstrated as design tools. The use of Sketchup for developing three-dimensional timber frame computer models from which drawings can be derived is demonstrated.
Participants are invited to bring their own projects and ideas for sharing and discussion. Several are selected for group review and problem solving.
Depending on students’ interests, other topics can be explored, such as: roof rafter layout and the use of the framing square; gambrel roof geometry and characteristics; and graphical layout systems for developing drawings following French and German traditional techniques. Students will be provided with handout materials and references for their own further study.